Def or DEF may refer to:
Defamation—also calumny, vilification, and traducement—is the communication of a false statement that harms the reputation of an individual person, business, product, group, government, religion, or nation.
Deforestation, clearance or clearing is the removal of a forest or stand of trees where the land is thereafter converted to a non-forest use.
Defibrillation is a treatment for life-threatening cardiac dysrhythmias, specifically ventricular fibrillation (VF) and non-perfusing ventricular tachycardia (VT).
Deflategate was a National Football League (NFL) controversy involving the allegation that the New England Patriots deliberately underinflated footballs used in the American Football Conference (AFC) Championship Game against the Indianapolis Colts on January 18, 2015 of the 2014–15 NFL playoffs.
Deferred Action for Childhood Arrivals (DACA) is an American immigration policy started by the Obama administration in June 2012 that allows certain undocumented immigrants to the United States who entered the country as minors to receive a renewable two-year period of deferred action from deportation and eligibility for a work permit.
What constitutes a definition of fascism and fascist governments is a highly disputed subject that has proved complicated and contentious.
A definition is a statement of the meaning of a term (a word, phrase, or other set of symbols). Definitions can be classified into two large categories, intensional definitions (which try to give the essence of a term) and extensional definitions (which proceed by listing the objects that a term describes).
The Defence Research and Development Organisation (DRDO) is an agency of the Republic of India, charged with the military's research and development, headquartered in New Delhi, India.
The Defenders is a set of fictional superhero groups with fluctuating membership appearing in American comic books published by Marvel Comics.